The simultaneous flow of oil-gas-water mixtures in pipes is a common occurrence in the petroleum industry. This type of flow is found in producing wells. Most well fluids are composed of oil and gas but during the life of the well the water content can increase greatly. Research into this area has defined a number of different flow regimes for such mixtures. The need to measure downhole flow rate, density and fluid fractions of oil-gas-water mixtures in the production string has been fundamental for many years. The device described herein enables determining these parameters, along with ambient pressure and temperature, to be measured using a modular flowmeter based on vortex shedding, energy harvesting, electro acoustic Technology (EAT), molded mandrels and DAS optical telemetry. Numerous modules can be installed across a pay field so that local flow conditions in different regions can be determined. A device is described which provides: a means to harvest energy from downhole fluid flow based on Vortex Induced Vibration (VIV). The energy is converted to electricity that is used for powering very low power electronic sensing devices such as Electro Acoustical Technology (EAT) devices, which piggy back on fiber optic Distributed Acoustic System (DAS) telemetry for data transmission.
Energy harvesting is the process by which energy readily available from the environment is captured and converted into usable electrical energy. Historically, downhole electrical power has been either via electrical wiring from the surface, limited life batteries, or turbines powered by drilling mud for MWD. All of these methods were used for creating significant power downhole. The advent of nano powered sensors, ultralow power microprocessors and other minimal powered devices opens up a new era for downhole telemetry when combined with fiber optic data transmission. This promises perpetually powered sensors that use very small amounts of energy. What is needed is a method for downhole energy harvesting to power this new generation of electronics. The major sources of energy downhole are fluid flow, vibration, acoustics and heat. While the system described below is based on the conversion of fluid flow using piezo electrics, conversion can also be accomplished using vibrating cantilevers, accelerometers, induction coils and magnets, impellers and other means. There must be fluid flow for the vortex energy harvester to work. Where no flow is present, vibration, acoustics or heat transfer can be utilized. In some cases all three can be utilized together.